how to delete namedtemporaryfile

callout on the "contains" filter. And this library is not designed for it, so users can't rely on the native functionality. The web framework for perfectionists with deadlines. Surely if a script has no need to reopen a temporary file, then it shouldn't care what the file's name is. My version does not delete the file until the context manager exits, and *if* the context manager exits due to an exception it leaves the file in place and reports its location, to aid me in debugging. Maybe NamedTemporaryFile should be retained for backward compatibility, but as a normal function, with the CM behaviour deprecated. Returns ------- The acceptable difference would be that __del__() closes (if necessary) /and/ deletes the file on disk, while close() merely closes the file. Trademarks are property of respective owners and stackexchange. verbose : bool, optional Whether to print out information about the save file, including the records read, and available variables. In my PR I used solution, proposed by Eryk. These are the top rated real world Python examples of tempfile.NamedTemporaryFile.write extracted from open source projects. I looked at the code in the django.core.files.temp module, and see it makes a distinction between Windows and other systems: [code] You can create temporary files which has a visible name on the file system which can be accessed via the name property. import tempfile . Jason R. Coombs jaraco@jaraco.com added the comment: def TemporaryFile ( mode='w+b', buffering=-1, encoding=None , newline=None, suffix=None None Create a temporary file. The only difference is that a file with a random filename is visible in the designated temp folder of operating system. ;-). tempfile.NamedTemporaryFile not particularly useful on Windows, 'tempfile.NamedTemporaryFile not particularly useful on Windows', aws-cloudformation/cloudformation-cli#924. It is the core of this issue. Have a question about this project? If delete is True, close() must delete the file. My solution involves introduction of the extra flag delete_on_close and making sure, that new situation is fully backwards compatible, because I did not feel I have an authority to propose anything which would break backwards compatibility (as Python 4.0 I think is not on the horizon yet). or mmap its contents, or otherwise access it however you like. (In contrast, tempfile.NamedTemporaryFile() provides a 'file' object and deletes the file as soon as that file object is closed, so the temporary file cannot be safely re-opened by another library or process.) Well occasionally send you account related emails. The downside is that the temporary file can't be moved to another directory except by an existing open (e.g. Select the file and press your Delete key, or click Delete on the Home tab of the ribbon. It takes a delete parameter which we can set as False to prevent the file from being deleted when it is closed. At least I and Ethan and Martin have expressed a desire for the default, preferred usage work well in a portable environment. Converting the issue to a feature request for 3.3 - there's no bug here, just an interaction with Windows that makes the existing behavioural options inconvenient. It returns a writeable file object, but that can be closed (and the documentation notes that for portability it *must* be closed before passing the name to another process for use). from tempfile import NamedTemporaryFile import shutil import csv In this code, we will learn how to perform CRUD tasks on files (i.e. What I think that means is that we need to maintain an open filehandle of *some* sort continually, but there's a point where the user can say "I'm done writing, I want to share this now". (Ignore previous comment; should have gone to #15659.). Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Ethan however thinks, that no extra flags are necessary at all, Eryk prefers to provide a way to omit O_TEMPORARY, but still use it by default, when it's omitted, CHANGING OF THE CURRENT BEHAVIOUR / BREAKING BACKWARDS COMPATIBILITY I don't know enough about how we protect this against race condition attacks, but I'm pretty sure that this API gives us the best chance we're likely to have of doing so in a cross-platform manner. This file too is deleted immediately upon closing it. OTOH, if the proposal is merely to change the way the file is opened Is hook_field_group_build_pre_render_alter deprecated in Is the social menu(p by default on PC) recent players Is UIApplication.shared.applicationIconBadgeNumber is mega evolving bugged in pixelmon 1.16.5? Paul Moore added the comment: Paul, thank you for moving this forward. The NamedTemporaryFile() function creates a file in the same way as TemporaryFile() but with a visible name in the file system. To do that, you need to close the file first (on Windows), which means you have to pass delete=False, which in turn means that you get no help in cleaning up the actual file resource, which as you can see from the code in tempfile.py is devilishly hard to do correctly. That's unlike any other CM I know of, where the scope ending is what triggers tidy-up. Do we have any actual examples of code that needs the current CM behaviour (as opposed to a general concern that someone might be using the functionality)? Solution 2 If anyone against it. However, the fix is simple, the only backwards-compatible issue is the file would still be there /while a context manager was in use/ after it had been closed (which conforms to most, if not all, users of context managers) and a file would be left on disk in the event of a hard crash (hopefully a rare occurrence). It is not acceptable for close() and __del__() to behave differently. You don't want to "rip out all the bits.". from django.core.files.temp import NamedTemporaryFile. The following are 30 code examples of django.core.files.temp.NamedTemporaryFile().You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. def project_to_header(fitsfile, header, use_montage=True, quiet=True, **kwargs): """ Light wrapper of montage with hcongrid as a backup Parameters ----- fitsfile : string a FITS file name header : pyfits.Header A pyfits Header instance with valid WCS to project to use_montage : bool Use montage or hcongrid (scipy's map_coordinates) quiet : bool Silence Montage's output Returns ----- np.ndarray . You can rate examples to help us improve the quality of examples. If __enter__() is called, The file can, on unix systems, be configured to delete on closure (set by delete param, default is True) or can be reopened later. After all, you can currently get deterministic cleanup (with a __del__ fallback) via: You need to be careful to make sure you keep the CM alive (or it will delete the file behind your back), but the idiom RDM described in the other issues handles that for you: As far as the API goes, I'm inclined to make a CM with the above behavour available as a new class method on NamedTemporaryFile: Although, for the stdlib version, I wouldn't suppress the OS Error (I'd follow what we currently do for TemporaryDirectory). delete=True # delete after file closed, current behavior Write some data into it. I am not sure. I don't think implementing TemporaryFile() in Windows is separate from this issue. You can create temporary files which has a visible name on the file system which can be accessed via the name property. NamedTemporaryFile() This function is similar to TemporaryFile() function. It states that accessing it a second time while it is still open. delete=AFTER_CM_EXIT_NO_EXCEPTION # delete after CM exit, unless this is due to an exception. dabrahams/zeroinstall@d76de03#L3R44 Nick, not to belabor this, but I guess you don't understand the use-case in question very well, or you'd see that delete=False doesn't cover it. Sign in to your account. I included that to highlight that it's possible. You signed in with another tab or window. file. I have no direct interest in Evgeny, would you be willing to update your PR (including adding the docs change, and tests to catch as many edge cases as you can think up) to match this behaviour? manager work as expected with delete=True (ie: doesn't delete until Note: The information provided in this video is as it is with no modifications.Thanks to many people who made this project happen. Eryk has argued for a delete_on_close flag that would need to be explicitly set to False, retaining the use of O_TEMPORARY in the default case, but there doesn't seem to be a lot of support for that. somone can come up with a single, concrete suggestion. create new records, read exisiting records, update exisiting records and delete exisiting records) Update the current code to be able to perofrm those 4 tasks based on choices provided for the user through the console screen Create means adding a new student . The file can, on unix systems, be configured to delete on closure (set by delete param, default is True) or can be reopened later. I agree with RDM's proposal in bpo-14514 that the replacement should be "delete on __exit__ but not on close". I have implemented a Windows-friendly solution to the latter case using Nick Coghlan's code. If there any issues, contact us on - htfyc dot hows dot tech #PYTHON:HowtousetempfileNamedTemporaryFile()? Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state. If they're unnamed (pre-deleted), there's less to go wrong in terms of cleanup. A solution would be to define NamedTemporaryFile as follows: [code] class NamedTemporaryFile (TemporaryFile): def init (self, kwargs): kwargs.pop ('delete', True) # TODO: handle this delete flag. Eryk Sun added the comment: I wasn't disagreeing with Ethan. Given the move away from GC-cleanups, you'd probably want an explicit unlink() method as well in that case. Information credits to stackoverflow, stackexchange network and user contributions. super(NamedTemporaryFile,self).init(kwargs). Related Topics . This approach would allow a user to opt in to the future behavior which has the desired effect of preferring the default behavior (in as little as two releases). O_TEMPORARY to be removed, which doesn't seem controversial among tempfile = namedtemporaryfile (delete=false, dir=self._temp_dir) # make sure we distribute data evenly if it's smaller than self.batchsize if "__len__" not in dir (c): c = list (c) # make it a list so we can compute its length batchsize = min (len I apologise - I got bogged down somewhere in the middle of the discussion on reimplementing bits of the CRT (your posts are so information-dense that my usual habit of skimming breaks down - that's not a complaint, though!). I can understand most of the arguments you make against close-without-delete, except those (like the above) that seem to come from a "you shouldn't want that; it's just wrong" stance. What problem are you trying to solve by this "unlinking trick"? Disclaimer: All information is provided as it is with no warranty of any kind. nuisance, and having to call a separate method doesn't sound very But I never subscribed to that view myself.). If __enter__() is called, close() closes the file but doesn't delete anything, and __exit__() closes the file (if open) and deletes it (even if it wasn't open). By clicking Sign up for GitHub, you agree to our terms of service and By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. Is this "unlinking trick" using some documented features of Windows? It doesn't need to unlink the file to make it anonymous. A subreddit for all questions related to programming in any language. In a release after the deprecation has been released, change the default to delete_when="exit" and drop support for None. By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. (My original over-complicated proposal was based on a mistaken belief that it had already been established that backward incompatibility was absolutely not allowed. Does it mean, that your suggestion to leave the O_TEMPORARY for TemporaryFile means, that NamedTemporaryFile needs to have a mechanism to know whether it was called as a TemporaryFile and then to have a different functionality in this case relative to the situation it would be called directly? PYTHON : How to use tempfile.NamedTemporaryFile()? NamedTemporaryFile() in Windows could switch to relying on the context manager to delete the file. The file can, on unix systems, be configured to delete on closure (set by delete param, default is True) or can be reopened later. Tim Golden, So we stop passing the O_TEMPORARY flag. the `tempfile` module to determine a temporary filename automatically, and will remove the temporary file upon successfully reading it in. [code], kwargs.pop('delete', True) # TODO: handle this delete flag To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Working out how to implement it can come after we know what people want it to do. Args: suffix: desired filename extension (e.g. I'd be sad if we ended up with an over-complicated solution for no better reason than an excess of caution over a backward compatibility issue that we're not sure will impact anyone. code [ Gift : Animated Search Engine : https://bit.ly/AnimSearch ] PYTHON : How to use tempfile.NamedTemporary. Programming . Davide, the @contextlib.contextmanager decorator effectively wraps the See msg390814. See msg390814. Django Software IMO, what's more important is whether NamedTemporaryFile is *useful* to people, and what they want to use it *for*. As with generator context managers, I'd also add in the "last ditch" cleanup behaviour in __del__. Here are the examples of the python api tempfile.NamedTemporaryFile taken from open source projects. that sounds fine. What's the proposal here? Looking at the various comments, I think we have 5 votes for deleting on CM exit when used as a CM, and no change in behaviour otherwise (me, Zachary, Ethan, Jason and Steve). We and our partners use cookies to Store and/or access information on a device. Prior to Windows 10 (tested back to Python 3.2 in Windows 2000), the unlink(name) call will leave the file linked in dir, but trying to access it with a new open will fail with an access-denied error. I'd assumed that it was somehow unacceptable, but you're right, and it's not clear if Eryk is agreeing or disagreeing with you (I assumed he was disagreeing, based mainly on the length and complexity of his response :-)) It didn't help that somehow Steve's reply wasn't visible when I posted mine. It probably needs getting rid of O_TEMPORARY, Learn Python Language - paramdescriptionmodemode to open file, default=w+bdeleteTo delete file on closure, default=Truesuffixfilename suffix,. "fixing" ;) NamedTemporaryFile was arduous, complicated, or had serious backwards-compatibility issues then I would completely agree with you. By the way, I still think it would be nicer just to have the context manager work as expected with delete=True (ie: doesn't delete until the end of the context manager, whether the file is closed or not). This was still causing some confusion, so I rewrote the section in the CS degree is taking all my free time and I cant learn How do you deal with how frustrating it is to learn Press J to jump to the feed. I do think this needs care to implement (and document!) Eryk, thank you for clarifying. (Especially since doing so would also breach backward compatibility guarantees). The consent submitted will only be used for data processing originating from this website. The first line is closing the temporary file, and the second is getting it's filename. Manage Settings By voting up you can indicate which examples are most useful and appropriate. My particular use case is actually pretty simple, and I suspect constitutes a fairly major proportion of what people want of this API: The key additional requirement is that this is done "safely" (by which I mean I don't have to think about race conditions, etc, as someone else has that covered). delete=AFTER_CLOSE # delete after file closed It doesn't matter when the file gets cleaned up, as long as it is cleaned up "eventually." The file is created securely, using the same rules as mkstemp (). bpo-14243: Optionally delete NamedTemporaryFile on content manager exit but not on file close, gh-58451: Add optional delete_on_close parameter to NamedTemporaryFile, https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew#caching_behavior, : Add optional delete_on_close parameter to NamedTemporaryFile (, : Add optional delete_on_close parameter to NamedTempor. Alternatively, it could be that because the file is still open in Python Windows won't let you open it using another application. I am trying to replace the insecure tempfile.mktemp() here (old code): pq_file = file_utils.extract_file_from_zip_onto_disk(zip_obj, pq_path, tempfile.mktemp()). There's a lot of technical discussion of implementation details here, but not much about use cases. Does it get removed inside the context manager of extract_file_from_zip()? If simply removing "delete on close" behaviour in the CM case is acceptable, then I'm 100% in favour of that. If "rescuing" (i.e. Do I need to close or delete created NamedTemporaryFile here? Basically, I may be wrong, but I feel that we should stop trying to "rescue" NamedTemporaryFile, and instead try providing an *alternative* that handles the cross-platform use case that started all of this. An example of data being processed may be a unique identifier stored in a cookie. My opinion is that no extra flags are necessary. which case delete on CM exit. Question: does everybody definitely agree then, that backwards compatibility shall definitely be altered, whether immediately or gradually? I didn't look back at the stuff from 2013 and earlier, I'll admit. 2005-2022 I agree. Creates a temporary file in the most secure manner possible. Note that an internal flag will be needed Is the minor backwards compatibility worth all that work? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. The safest and most portable approach is to close the file, call the other process and then unlink the file manually: with tempfile.NamedTemporaryFile(delete=False) as f: try: f.write(b'data') f.close() subprocess.Popen(['binutil', f.name, .]) If there is no __enter__(), close() also deletes the OTOH, if the proposal is merely to change the way the file is opened on Windows so that it can be opened again without closing it first, that sounds fine. My preferred solution would be to replace the binary delete argument of the current NamedTemporaryFile implementation with finer-grained options: I replied twice that I thought using the CM exit instead of O_TEMPORARY is okay for NamedTemporaryFile() -- but only if a separate implementation of TemporaryFile() that uses O_TEMPORARY is added at the same time. I may be mistaken, but I see that you are proposing some trick with first unlinking the file and then employing it as a temporary file using previously known fd. img_temp = NamedTemporaryFile(delete=True) Let's look at a simple example now. Daniel, Nick, shouldn't the context manager yield f within a with block? Does it get removed inside the context manager of extract_file_from_zip()? NamedTemporaryFile isn't a public API there isn't any reference to this class in the documentation: https://docs.djangoproject.com/search/?q=NamedTemporaryFile&release=5. The only thing I want to point out is that your suggestion also includes this "unlinking trick" (sorry, may be there is a better description for this), which seems to be separate/extra to the usage of O_TEMPORARY. CONCLUSION: I'm suggesting that it might make sense to allow an explicit close-without-delete as an /extension/ of the current interface. Firstly, yes you will need to delete the NamedTemporaryFile because you set delete to False. ", and then I went, "oh, right". Steve also wants by a job object). By voting up you can indicate which examples are most useful and appropriate. On Sat, Jun 30, 2012 at 1:46 AM, Davide Rizzo wrote: Davide Rizzo added the comment: Python tracker I'm not marking it as a dup because my proposal is really a new feature. [1] https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew#caching_behavior. A solution would be to define NamedTemporaryFile as follows: For example, consider the following case: I assume we'd want a close in (1) to delete the file, but a close in (2) to leave it open until the CM exit. def save_to_model (file_field, file_name): img_temp = NamedTemporaryFile (delete=True) img_temp.write (open (os.path.join (settings.MEDIA_ROOT, file_name), 'r').read ()) img_temp.flush () file_field.save (os.path.basename (file_name), File (img_temp), save=False) # delete files after saving in models delete_file (file_name) Example #12 0 Will we need to create separate unit tests for this issue? A file that's in a deleted state is only accessible by existing opens. The text was updated successfully, but these errors were encountered: NamedTemporaryFile is too hard to use portably when you need to open the file by name after writing it. Eryk Sun added the comment: At the moment, the TemporaryFile directly reuses NamedTemporaryFile for none-posix or cygwin systems. Even as a context manager my first thought in reading it was "delete after what? The following will create and open a named temporary file and write 'Hello World!' to that file. :). So, no, we're not going to back away from the explicit guarantee in the NamedTemporaryFile docs: "If delete is true (the default), the file is deleted as soon as it is closed." __exit__() closes the file (if open) and deletes it (even if it If there is a separate class method for different behavior, it should be for the specialized behavior, not for the preferred, portable behavior. via SetFileInformationByHandle: FileRenameInfo). needed on windows systems to access file This is due to a security feature. delete=AFTER_CM_EXIT # delete after context manager exits Eryk, I agree, that implementing TemporaryFile() in Windows goes hand in hand with the decision to stop using O_TEMPORARY in NamedTemporaryFile(). However, according to http://docs.python.org/library/tempfile.html#tempfile.NamedTemporaryFile NamedTemporaryFile should be able to handle delete as well! everything subsequent occurs in the __exit__() method. Press and hold the CTRL key as you select multiple files to delete. Rather than add a NamedTemporaryFile.delete_after() classmethod, would it not be simpler to just add a close_without_unlink() method to NamedTemporaryFile? tf = tempfile.NamedTemporaryFile(delete=False) and then delete the file manually once you've finished viewing it in the other application. On POSIX (only), a process that is terminated abruptly with SIGKILL cannot automatically delete any NamedTemporaryFiles it created. By the way, I still think it would be nicer just to have the context Do we need to have a separate issue raised for this problem? I disagree that it's unacceptable for close() and __del__() to behave differently. That said, I understand the move toward deprecating (in the informal sense) cleanups that rely on GC. If you can in fact "change the way the file is opened on Windows so that it can be opened again without closing it first," that would be fine with me. The O_TEMPORARY flag MUST NOT be used if the goal is to make NamedTemporaryFile() "particularly useful on Windows". We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. I also want O_SHORT_LIVED. Requiring delete_on_close=False violates that expectation. wasn't open). This opens the file with the attribute FILE_ATTRIBUTE_TEMPORARY [1], which tells the cache manager to try to keep the file contents in memory instead of flushing data to disk. A NamedTemporaryFile whose close() deterministically managed the open/closed state but not the existence of the file would be consistent with file. Indeed, the current behaviour under Windows seems to be kind of a Removing O_TEMPORARY is not an afterthought here. as an alternative, serialized # objects are written to a file and loaded through textfile (). A file that's opened with DELETE access cannot be reopened in most cases, because most opens do not share delete access, but it also can't be closed to allow it to be reopened because the OS will delete it. case-insensitive equality checks, as well as putting in a stronger Steve also wants O_TEMPORARY to be removed, which doesn't seem controversial among this group of people. delete_on_close=False violates that expectation. This behavior change is fine if O_TEMPORARY isn't used. Most of my last comment, however, was dedicated to implementing TemporaryFile() if this change is applied, instead of leaving it as an alias for NamedTemporaryFile().

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